Method of electric signaling.



o. KINSLEY; METHOD-0F ELECTRIC SIGNALING.

APPLIOATIOHIILED AUGJZ, 1903. 1 1,126,641. Patented Jan. '26, 1915.

4 SHEETS-SHEET 1.

N B F s m'ruwwwa 000 ozrooooo 7 G. KINSLEY. METHOD OF ELECTRICSIGNALING.

'APPLIOATION FILED AUG. 12, 1903.

I Patented Jan. '26, 1915.

4 sums-sum zj C. KINSLEY.

METHOD OF ELECTRIC SIGNALING. APPLICATION FILED AUG. 12, 1903,

Patented Jan. 26, 1915.

L1QL

4 SHEETS-SHEET 3.

C. KINSLEY.

METHOD OF ELECTRIC SIGNALING. APPLICATION FILED AUG. 12, 1503.

Patented 52111.26, 19.15.

A SHEETS-SHEET 4.

Ll/VE f LINE cam. KInsLEY, or CHICAGO, ILLINOIS.

METHOD or ELECTRIC SIGNALING.

Speeification'of Letters Patent.

Patented Jan. 26, 1915.

Original application filed February 2, 1903, Serial No. 141,524. Dividedand this application filed August 12,1903. Serial in. 169,228.

To all whom it may concern Be it known that I, CARL KmsLnY, a citizen ofthe United States, residing at Chicago, county of Cook, and State ofIllinois. have invented a new and useful Method of Electric Signaling,of which the following is a specification.

My invention relates to electrical signaling and particularly toimprovements in the methods commonly employed in telegraphy.

It has. for its object the improvement of high speed transmission, tothe end that legible indications or characters may be produced upon arecord surface, controlled from a transmitting station at higher ratesof speed than have ever heretofore been attainable.

This application is to be taken as a division of my co-pendingapplication for telegraphic system and apparatus, filed Feb. 2, 1903, S.No. 141,524, in which I have described one form of apparatus by which mypresent invention may be practised, and have indicated some modifiedforms.

For the purpose of the present application, I have illustrated and shalldescribe the same system and the same apparatus as in the otherapplication referred to.

In high speed telegraphic transmission as heretofore practised, manydifliculties have been discovered and overcome from time to time, butthere still remain limitations which appear to be inherent principallyin the methods of receiving. Under present conditions it is quitepossible to transmit many more characters in a given time than can beproperly recorded by the methods in use. Most transmitters employ aperforated tape or its equivalent, and as the contact brushes resting onthe tape are short and readily adjusted to any tension desired,practically the only limiting factors are the i line constants and thoseof the receiver. My

present invention is therefore particularly directed to improved methodsof receiving messages. y

Speaking in terms of the apparatus, two types of receivers have beenmost generally used. These are the mechanical printer and the chemicalrecorder. Each has its. own

distinctive limitations, which I will point out.

It-has been said by competent authority that no system of this kindwherein mass has to be moved in response to the line impulses, Will everbring down the cost of telegraph transmission to a point where it willrob the mails. In general this is true. It is quite true of themechanical printers now in commercial or semi-commercial use. In some ofthese, alphabetical type levers have to be swung, or levers shifted,through a considerable path to print. Moreover such type bars or leversare controlled by printing magnets which are themselves controlled byline relays. This means that the inertia of all the moving parts of theprinter is augmented by the inertia of the relay armatures, as well asby the magnetic reluctance in both printing magnets and relays, theaggregate time loss being of necessity fatal to the receipt of messagesat a higher rate than perhaps one hundred words per minute, and perhapsnot that. The employment of relays in such cases is almost imperative,in spite of the time loss they entail, because the changes in current ona line of any length are not sharp enough except at very moderate speedsto make clearly differentiated signals, and moreover, in order to cutdown the number of impulses to a practicable point polarity is resortedto, and the relays made selective. The other class of receivers, that isthe chemical recorders, have faults and limitations almost as serious asthe printers. The recording is usually done on a tape, which can bedriven under contact pens as rapidly as the transmitting tape, or nearlyso. In so driving. it the contact pens usually rest on its sur fl face,and as current passes through them marks are made by chemicaldecomposition and recomposition. Over short lines, with strong currents,fairly good results can be obtained in this Way, but as soon as longerlines are tried (where in practice the greatest need for such systemsexist) trouble hegins. The variations in current at the receiving end,passing at a frequency of 25,000-

or more impulses pcr'minute, are almost smoothed out, so that the actionon the tape is slight: As decomposition takes place in thesensitizing'medium, moreover, part of the products of such decompositionadhere to the pen points, and cause a continuous chemical eflect on thetape-under the pens, making lines or tailings that are quite plain. Now,when, the weak increases or changesin the line'current come in, andfrecording action .takesplace, the added de -'composition is hardly tobe noticed, and in fact at very high speeds the record is hardlylegible, the tape soon after starting show- 7 ing continuous white orlight lines, with scarcely a variation. At lower speeds, even, thisfault makes the record untrustworthy.

Every effort has been made by those interested in chemical telegraphs toeliminate v. the feature of continuous action, with resulting tailings,but so far, without practical success.

-:The ideal commercial system, is that .wherein the message is directlyprinted in J legible characters, and in such 'shape and on such materialthat it can be delivered to fltheperson for whom it is intended, withoutcopying or other handling. My invention is intended to accomplish this,which heretofore has been posible only to the class of so-calledprinting telegraphs, the chemical recorders employinga code.

" found it expedient to combine features of In developing my purpose,and in seeking to] improve the existing methods, I have v the two oldmethods in such a manner as gmutually reinforce their advantages. 80"

mutually to neutralize their defects and to It may be true that nosystem wherein masses have to bemoved bodily will ever attaintheoretical. freedom from speed limitation, or even attainthe ultimatespeed at which instruments we, can gradually raise the resultant-speeduntil the theoretical limit is approached; but although this has alwaysbeen apparent, it has not heretofore been possible, for mechanicalreasons, to reduce the inertia, which means the number, or the mass, orboth, of the receiver parts, beyond a certain point. I have found itpossible to l to continue the reduction beyond any limits heretoforereached. To do this I have discarded mechanical printing mechanism,

a whether of the impact type or others, and

while I directly record legible characters, I substitute electricalaction for the printing,

,thus borrowing one feature from the chemical methods. As the impressiondoes not I depend on the possession of mass, or the momentum of theprinting member, I am en- 1 'abled to employ greatly attenuated masses,

approaching the theoretical limit to which I have referred. Although theelectrical v vprinting necessitates contacts and a traveling surface,obviously there will be no tailings, because there is not constantcontact. I My invention consists essentially in prmtproposed rate oftransmission. This natural period is higher than the free period byreason of the repulsive force caused by the signals and also thereaction of the resilient printing members and the elastic receivingsurface.

By making the natural period of my receiver very high, and byattenuating the moving masses, I increase the range of responsivenesswidely; and this is an important feature of my invention. Obviously, itv is quite possible to make such parts as pens or levers short enough tohave a high period, but such division if possessing considerable masswould be limited to approximately one frequency of transmitted impulses,by reason of their mass; andwhile in some cases this might be desirable,as,

where resonant selectivity is desired, in general it is rather thereverse, as accurate re-' ceiving should not be dependentupon fineadjustments or regulation, which are easily attainable in thelaboratory, but diflicult to I maintain in practice.

It is possible,by using small and light masses to cover a wide range oftransmission, and to reach a periodicity above anything possible oftransmission over lines of today. My method contemplates furtherincreases in speed, however, by the employment of changes in bothpolarity and current strength, so that the numberof impulses per Wordcan be reduced? One embodiment of my invention consists magnets areconnected to line so-that proper impulses thereover will efl'ect therelease and the reattraction of the contacts, causing them to touch andto leave the surface as desired. In some cases the local circuit can bedispensed with, and the contacts and platen included in a branch of theline to derive current therefrom. I have found the local circuitsatisfactory, however, as the record is uniform andfstrong. The contactsare usually pens of resilient material attached to the poles ofpermanent magnets so as to be normally held up in distorted position.Coils on the magnet poles permit the line impulses to vary or reversethe magnetization at will, and the use of polar magnets permits also aselective arrangement whereby a greater number of magnets can.

of a moving chemically-sensitized surface mediate losses.

be controlled over one or two conductors than would otherwise bepossible. As the pens are normally held up, the attractive force of themagnets can be nearly balanced against their resilience, so that a Veryslight change in the magnetization, due to a correspondingly slightchange in line current, will release the pens, which snap down to thesurface by their own resilient action, and snap back to the magnet bythe reaction as Well as by the attractive force received upon cessationof the line current. The pens are small and light, and as they are actedon directly by the magnets, there are no inter- The action is absolutelycertain, because 'the instant a pen starts away from the magnet pole wehave a cumulative force acting against a diminishing resistance, withacceleration such that its stroke will surely be made; and to fullyinsure this I may proportion the parts so that the natural period of thepens in vibration would be approximately the same as the normalfrequency of transmission. I have not found this necessary, however, asthe results are excellent without it. The frequency of the currentimpulses is always lower than the period of the pens, as I can increasethe period of the pens without trouble, by shortening them. The limit ofcurrent frequency is therefore resonance, as stated.

Referring to the accompanying drawings, wherein the same letters ofreference point out the same parts throughout, Figure 1 is a diagram ofa complete system embodying my invention. Fig. 2 is a detail view ofparts of the transmitter. Fig. 3 is a similar detail of the paper feed.Fig. 4 shows a section detached from the transmittingtape. Fig. 5 is aside view partly in section, and Fig. 6 is a bottom view showing therecording mechanism. Fig. 7 is a similar view to Fig. 5, showing amodification of the recording magnet structure. Fig. 8 is a diagram of asystem employing certain modified arrangements of transmitter andreceiver. Figs. 9 and 10 are diagrams showing further modifications.Fig. 11 is a diagram of a telegraph system embodying my invention andcluplexed by the bridge method. Fig. 12 shows an alphabet built up ofelements according to my invention.

As before stated, my invention resides particularly in the methods ofreceiving. I

employ a known type of transmitting mechanism, in which I have made someimprovements, however. Referring to Fig. 1, linewires 1 and 2 areemployed, leading from the transmitting station T to the receivingstation M. In operation, I automatically record the messages in legiblecharacters at the receiving station through the agency of a number ofpolarized printing magnets, Worked by positive and negative impulsessent over the line-wires 1 and 2 separately or simultaneously. Themechanical arrangement for controlling the transmission of theseimpulses is indicated in Figs. 2, 3, and i. A paper tape P is taken fromreel P and passing over guide rolls 19-29 is led over a platen t andunder a set of springs or contact brushes t etc. shown in p an in Fig.1), thence under another guide or friction roll 79 and to a toothedfeednvheel and companion, 72*, 72 The teeth [7 of the feed-wheel turnwithin an annular recess 72 of, the companion, and engage with a centralseries of perforations 79 of the paper tape. to prevent slipping. Thisis best shown in Fig. 4. The brushes it, etc. are permitted to makecontact at predetermined times and in predetermined order with theplaten 15 1 through perforations punched in. the tape in any suitablemanner. As the method of preparing tape in this way is well understoodin the art it is unnecessary for me to describe it. All messages arepunched in the tape as a preliminary to the tnansmitting operation.

The circuits of the transmitter are best shown in Fig. 1. Here B-B'-B -Bare the main transmitting batteries, arranged in pairs with polesreversed to line, and connected to the conductors 1 and 2 by the branchwires 3-5-6. On the other side, battery B is connected to brushes 6 andf by wires 3-30 and 3-31 respectively; battery B is connected to brushest and t by wires 4-0 and 4-41; battery B is connected to brushes t andplaten section t by the wires 5-50 and 5-51 respectively; and battery Bis connected to the brush t and the platen section 25 by the wires 6-60and 6-61 respectively. The platen section 25 is grounded by the wire 18.By this arrangement it is possible to send current impulses of eitherpolarity over either or both line wires and to ground, or over themetallic circuit, as follows: If brush 6 is permitted to touch theplatent positive current goes to line from battery B; if brush t touches,negative current from battery B goes to line (this being wire 2 in bothcases) if brush. t touches, positive current from battery B goes to linewire 1; if brush t touches, negative current from battery B goes to linewire 1; if brush t touches platen section t current flows in themetallic circuit 1-2 with positive pole of combined batteries B'-B towire 1; if brush t touches platen section 23 current will flow in themetallic circuit from the combined batteries B-B in a reverseddirection, 2'. 0. with positive to wire 2. Thus all combinations can bemade, and any effect or group of effects produced by the arrangement ofholes in the tape to permit corresponding arrangement of the brushcontacts.

At the receiving station M I. employ the polarized electromagnets AA'-AA and A", each magnet when operatively affected producing a certain markconstituting an element of a. character, on a re cording surface, andone or more of the marks being imprinted for each letter or figure of amessage. The mechanical features of the receiving magnets will bepointed out presently. Their connections are shown in Fig.- 1. A bridge710 across the line-wires 12 has two parallel branches 8 and 9,containing the coils of the. receiving magnets A and A respecti ely. Aground connection from wire 1 by way of wires 14: and 17 7 containsarallel branches 15 and 16 with the coils 0 receiving magnets A and Awhile a similar ground connection from wire 2 by way of wires 11 and 17contains parallel branches 12 and 13, with the coils of receivingmagnets A and ,A The ma nets A A are all polarized, 01"l3l181! coilswound so that current of one signsay positive-will operatethem; whilemag-v nets A'-A and A are oppositely polarized or wound. Thus current ofone direction in the metallic circuit will operate one magnet A or A butnot the other; while the re verse current will oppositely affect thepair. Similarly any of the other magnets may be made to operate ornot,"one unit of each pair being available at the same time by sendingcurrent of proper. directionover the appropriate circuit.

Turning now to Figs. 5,6, and 7, I Wlll describe the structural featuresof .the receiver. In Fig. 5 the form of magnet ordinarily employed in mywork is shown. A horseshoe permanent magnet A is provided with soft ironpole pieces a and a, the former carrying a coil a and having aprojecting pole face a, while the latter carries a spring member a ofmagnetic material, such for instance as a steel watch-spring, thisspring being rigidly attached to the pole a, and extending over in frontof the pole face a b which it is normally attracted to comp etc themagnetic circuit. In attaching the watch-spring to the pole piece a Itake care that the natural bent is away from the pole face a, so thatwhen attracted thereby the spring will be distorted from its natural'shape and will be under tension.

Fig. 6 shows a bottom View of the complete set of receiving magnets,ofwhich only one unit is shown in Fig. 5. The springs are arranged withtheir outer ends separated radially from a common point, and their innerends nested so that the character that needs all the elements or severalof them may be struck at one blow if desired. -At the end of each springa type face or printing tip or attachment a is secured. This may be ofthe same material as the spring, but sometimes I find it necessary touse a .difierent metal, which may be aluminum,

although not necessarily,

platinum, or what not, according to the solution used on the recordingsurface, as will presently appear. In Fig. 6' these tips or attachmentsare clearl seen, forming three horizontal lines on t e left, and twoshort vertical'and an inclined line on the right, all in black and heavylines in the drawing, to be clear, although in practice they are lightand thin. The overlying coils a a a a a -a are shown in dotted lines soas to avoid confusion.

he spring-a is prevented from stlckmg to the pole face a by means of' aninterposed non-magnetic stop, which may be a copper pin slightlyprojecting from the pole face,

or an electrolyticdeposit of copper, or the 7 ju'stable on the pole iecea, so that its ten- The simplest way of sion may be regulate doing thisis shown in Fig. 5, where thee'nd of the sp'ringrests on a curved faceand is The recording surface upon which the pens a make. their imprints,is preferably,

over a platen in the same manner as the transmitting tape shown in Fig.2, the feedwheel having no teeth'however. I do not limit myself to thisform of recording surface, as I may use a cylindrical surface fed alonglongitudinally as it revolves under the pens, so as to produce a spiralrecord. .I find the paper tape the most generally satis factory, howeveThe tape (which may obviously be of any suitable material) is indicatedin Fig. 5 directly below the printing magnet, passing over a platen a ofconducting material. This tape is chemically sensitized with any one ofthe several solutions commonly employed for that purpose. Such asolution is ferrocyanid of potassium, mixed with ammonium nitrate toinsure moisture of the tape. With this solution the printing tip orattachment a should be of iron, the spring and tip being connected bywire 19 with the positive pole of a printin battery b, and the platen aby a wire 20 with the negative pole. Several other solutions can beused, the material of the tip bein necessarily varied with the solution,as wel understood by those'who have used such apparatus.

The operation of the printin magnets can now be understood. When t ereis no current in the line the springs a are all held attracted and undertension by the perma-' a paper tape fed held thereon at any desiredangle by a fiat binder and a pair of adjusting screws.

upon such contact there will be an instantaneous flow of current fromthe battery I) through the circuit 1920 and through the pen, the tape,and the platen. The eifeet of the momentary impulse ceasing, the spring01 is again attracted, leaving its imprint chemically produced on thetape.

The tape P, during the operatlon of the apparatus, is constantly fedalong under the pens. Owing to the small mass and high naturalperiod ofvibration of each pen. the duration of impact of the pen on the tape isexceedingly short, so short, in fact, that even though the tape has acomparatively high speed of travel, its movement during the impact isinappreciable. Thus, there is no tendency to produce tailings, nor anydistortion of the imprints of the type faces.

The impulses are so timed by the perforations in the transmitting tapethat each pen is caused to make its imprint at just the proper time togive it the desired horizontal spacing in the line of print. In thismanner, is not only the spacing between letters and other characterssecured, but, also, the horizontal spacing between the various elementalmarks of which any character is built up. This means that the times ofnm pact of the various elemental type faces are so coiirdinated withrespect to the speed of the receiving surface as to build up completecharacters by combinations of the successive imprints.

It is to be noted that I do not in any sense tune my resilient printingpens so that their natural rate of vibration coincides with the rate atwhich the operating impulses occur. This latter rate is a variablebetween wide limits. It is not important or generally desirable toattempt to tune the pen to the rate at which the impulses are sent. butit is important that each pen shall have such a high natural rate ofvibration that when it is released by its electromagnet it will snapdown against the paper and rebound into the control of the magnet beforethe next impulse of the same character comes. In other words, thenatural period of vibration of the printing elements should be at leastas short, and preferably shorter, than the shortest interval betweenimpulses of the same character. By maintaining this simple relationbetween the natural rate of vibration of the pen and the shortest of theintervals between impulses that would operate the pen, I preventconfusion and false signals. This method assuresthe pen being alwaysbrought back into the control of its magnet before its next operatingimpulse arrives. Its time of release is thus rendered always perfectlydefinite as controlled by the prepared transmitting tape.

If required, I can make the natural period of the pens practicallyidentical with respond instantly to any weakening in the magnetic force,that holds them, and by adjusting them ,until their retractile force isjust over-balancedby the magnetic force, a very narrow working margin ofcurrent can be relied upon to act with certainty, this being of greatimportance where the instruments are to be worked over long lines.

In Fig. 7 a modification of the printing magnet is shown, in which thepen and one pole of the magnet are above the tape 2, and the other polewith the coil a are below the tape. In this case the apparatus works byattraction, the spring being adjusted barely to resist the attractiveforce of the pole-face a, so that a slight strengthening thereof willsnap it down on the tape. I] am here able to work on a narrow margin, :1so.

In Fig. 8 I show the same transmitting apparatus as in Fig. 1, but withgenerators in the shape of dynamo machines instead of batteries. Thegenerator G has its poles connected through wires 3 and 4 to the pens Jand t while generator G is connected to the pens t t, with sideconnections to the other pens and platen sections as in Fig. 1. Acrossthe terminals of the generator G is bridged a non-inductive resistanceR, to the middle point of which line wire 1 is connected. Thisresistance can be made of any magnitude desired, to regulate the voltageon the line. W'hatever brushes are in circuit, it will be found upontracing out the connections that one half of this resistance will alwaysbe in circuit with the generator. Thus, if brush t touch platen t andall the others remain insulated, the circuit will be from groundby wire18 to the platen, by brush t and wire 4 to, the generator G, to theupper end of the resistance R, down to its middle point, and so to line.The circuits of the other brushes may be similarly traced.

Resistance R bridges the generator terminal G, and has its middle pointconnected to line wire The functions are the same as in the case ofresistance R. The use of these resistances, and their character, enablessparking at the transmitting brushes tobe practicallv eliminated.

At the receiving station in Fig.8, Ihave shown the magnet coils of A Aconnected magnets at the receiving station, permitting 4 thisway, too,an additional selective prinrespond, but those ciple being available,more than the six magnets shown can be employed. Thus, in Fig. 10 asystem is'shown employing eight the use of eightinstead' of six elementsfor printing. Moreover, since the selective use of strength as well aspolaritg is depended upon, it is not necessary to ivide the impulsesbetween two or three circuits, and consequently one wire only is shown.In this figure the platen t is common to all the transmitting brushes,and is grounded by the wire 18. The generator G has its terminalsbridged, by the resistance R-R', from the middle point of which the linewire is led off, at g. The springs'tflt, t, t, t, v t andt are connectedto the points 1, r, 80

1 ,7 9', 1'20" and 1", respectively, on the coil R R. If now the springt be permitted to touch the platen 25 9, a current of strength -4 willbe sent to line by the following circuit: ground, wire 18, platen 29sprin 25, wire 3, generator G, wire 4, resistance point 9 and to line.If spring t be allowed to touch the laten -a current of strength 3 willgo to line, the circuit being from ground to p aten, to spring at, topoint r, to point 1, to generator, and through-resistance R to line. Thesucceeding springs, when touching,- send decreasing portions of positivecurrent to line in their order, until the point 9 is reached, when thesprings' t, 45

t, t and t" send increasing strengths of. negative current to line, thecircuit of spring t, forexample, being as follows: ground to platen,tospringt, to point 1", to point r, to generator, to point 1' to point9, and to line. By'touching the proper spring to the platen, therefore,any one of four current strengths, of either direction, can be sent toline, and any of the receiving magnets operated.-

It will be observed that for each increase in current strength not onlywill the particular magnet responding to that strength elow it which areof the proper polarity. This makes it possible to group the charactersand letters so that-several magnets can be worked and several elementsprinted to form a complete letter by a single'impulse. This increasesthe speed of transmission considerably. Where the characters are suchthat the single wire gives an insuflicient number of combinations, twowires may be employed as in the other figures. I consider this animportant part of my invention.

Fig. 11 shows a series arrangement of the receiving magnets similar tothat in Fig. 10, but duplexed by the bridge method. This is intended toshow the flexibility of the system. It readily lends itself to any ofthe ordinary methods of duplexing or even of quadruplexing which it isunnecessary to describe here. In Fig. 11,-the transmitting station isequipped with the strength and polarity transmitter shown in Fig. 10,and the same series arrangement of receiving magnets. At each terminalstation the receiving magnets are included between points 1 and 2,connected through resistances R, R or R R to the transmitter; and toline on one side, 1, and ground through a condenser C on the other, 2.The points 1 and 2 are ofequal potential for outgoing or homeelectromotive forces and currents, but the receiv ng magnets of courserespond to the incoming impulses the same as in Fi 10. Two line-wiresmay be used and eac duplexed in the same way.

Fig. 9 shows mly system equipped with transformers for t e receivingstation, and I have found that the impulses I use in transmission willproduce excellent results through such media. Inasmuch as the impulsesare momentary, the secondary discharges are sufiicient for the purposeof detaching the receiving springs from the magnet faces, and the latterimmediately resume their normal condition, with less lag, per haps, thanwhen directly in the line circuit. As shown, the transmitting station isfitted with the form of transmitter described in connection with Fig. 2and Fig. 3, while the receivers are all in parallel branches of separatelocal circuits connected to the secondaries of the transformers X, Y, Z,the primaries of which are across the line, and from the two sides ofline to ground. The strength and polarity combination can also beefiected with transformers without difliculty, although I have notdeemed ,it neces sary to illustrate it.

I have thus fully and explicitly described one form of apparatus, withseveral circuit arrangements, in which my present invention may beembodied and by means of which it may be practised. It will be ap-'parent, however, that the method'which I here set forth may bepractised-by means. of widely difierent apparatus and circuits fromthose shown. Thus, the speed of any telegraph receiver, and in fact ofany signal receiver, may be raised by mechanically tuning its movingmechanical parts so that I and in order to extend this both ways it 1sexpedient to have the periodicity of the parts considerably above thatof the current 15. the feed of the record surface is momenmean:

. moving masses light, and this is of great importance practically, forit avoids the necessity of any close regulation in transmitting.Variations of a quite considerable percentagedo not affect the receivingaccording to my method. The pens or levers will have a considerablerange of responsive delicacy,

changes.

In most printingtelegraphs in use to-day tarily checked during theprinting act when impact occurs between the printing member or type andthe record member, Which is usually a paper tape.

per minute are caused to take place, a stop page of the feed mechanismor even the checking of the rapidly moving tape for each characterprinted would be an abso-. lute impossibility. vThe inertia of themoving parts and the physical laws bearing on the same would forbid anysuch operation ,except at low speeds.

According to my method I do not check the tape nor the feedingmechanism. On

the contrary I strive to make the movement of mytape as rapid, assmooth, and as regular as possible. Of course, the higher the speed oftransmission and the greater the number of characters rinted per second,the greater the speed of the tape must be;

but by employing the methods I have setforth and which I am about toclaim, .it is a very noteworthy fact that this speed of the tape-feedcan be varied between wide limits without affecting the legibility ofthe message. The reasons for this permissible variation in speed of tapefeed are as follows: The time of impact of the pens against-thereceiving tape is so very short that even at the highest tape feeds nodistortion of the printed mark occurs, due 'to tape movement duringimpact.

Furthermore, since the letters or other complete characters are formedby combinations of the various elemental imprints, it follows thatvariation of the receiving tape speed without'varying the rate at whichthe'immake narrower the received "pulses are being sent will merelywiden or characters. Thus, for illustration, I will assume-that acertain definite time is required to transmit the letter M. If duringthis time the receiving tape moves, say ths of an inch, the letter Mwill appear of that width. If,

however, the tape moves slower, say, only -},th of an inch during thattime, then-the letter M' will appear only vi th of an inch wide.Variations in tape feed, therefore,

Obviously, in high. speed work, where thousands of impacts whateverfol-m it may take.

while they do. alter somewhat the general appearance of the received,characters, do not alter their legibility unless they are extreme. Theattenuation of the receiving pensprevents their being limited inresponsiveness 'to a single frequency, and the method of printing byelectric contact with a chemically sensitized surface enables me todisregard time ih that connection, as the printing act seems to beaccomplished instantaneously.

. I believe I am the first to discover that the theoretical limit ofspeed in printing recorders, or'mechanical recorders of any kind, can beapproached by tuning the moving parts of-the receiver to the same as ora higher periodicity than that of the line im-v pulses or changes; I amthe first to present a practicable scheme for the adjustment of linefrequencies, and instrument constants, such that not only will theinstrument respond to every change in the current with facility, but theprogression of the record can be made continuous, no time of impact ofappreciable length being required and therefore no retardation in themachine, These things are not only important to high speed operation,they are vital. I print a legible record, and so far as my work has goneI am able to print at the highest frequencies permissible, oftransmission.

In my companion application, to which reference is made herein, I haveclaimed the apparatus embodying the principles I have here presented. Inthe present case I have endeavored to present a broader statement thanis possible in termsof the apparatus.

I wish it to be understood that the. terms of definition I use hereinare intended to be and the period or periodicity of the receiving partssuch as the printing levers, are Well understood, being measured inunits. of change, per unit of time. In the following claims I shall makeuse of a similar standard for expressing the third element or therelation between the feed of the recording surface or the record membersof the receiver, and the actuating or printing members thereof. Thus,for a tape, this may be expressed as the units of passage (or change)per unit ofv time, meaning by unit of passage the space of one characterin the feed; for other types of recording machines, the units ofrecording movement collateral ments which respond directly to thecurrent changes, may be taken per unit of time.

"or incident to the initial controlling movesetting mec refer to interms of its period, measured in.

units of progression per unit of time. By this means I=-am enabled toexpress the gist of my invention in briefer and clearer terms than wouldotherwise be the case. The underlying idea is independent of anymechanism, but embraces all mechanism by means of which impulses at ahigh speed of transmission are to be recorded or rendered intelligible.Stripped of all non-essentials it may be stated as follows: To recordsuccessfully high frequency current chan es, the parts controlled, whichdirectly trans ate the electrical changes into mechanical motion, musthave a natural period of the same order as that of the transmittedimpulses, and preferably higher; the working parts of the recordingmechanism must progress steadily, having a period of their own, withoutinterruption or interference due to the line im ulses or controllingarts; and finally t e controlling parts, orming the link between lineimpulses, and recording members, must cooperate with the latter,whatever be the function performed, for a time so brief in comparison tothe unit of progression as to have no disturbing effect on the record orthe recording members. In this specification and in my claims I make useof the expression high speed as applied to my method. While I do notcare'to confine myself to any particular frequency, or to frequencies ofany given order, I wish to make it plain that there is a widedistinction between the speeds I use and those of the ordinary printingtelegraphs, the latter being below. 100 per minute, and

my speeds ranging from several hundred to a thousand or more words perminute. This distinction is well recognized in the art,-

callin for different classes of apparatus and d fferent methods.

It isto be understood that by the use of the word F alphabet is meantall of the letters therein and all of the numerals.

In the following claims I shall use cer-.

tain expressions which may be thus defined: By potential driving force Imean a force present and due to potential energy stored up in each oneof the group of rin't fjiingagencies or pens. As described, thepotential ener y is stored up by distorting a; spring, wh1c is a fixedpart of eachpf said a agencies, along a path ds, when the potentialenergy may be expressed by the equation '1 E.=frds.

F is the force of the spring which may vary at each point in the path,and is called the potential driving force. The distortion,

of this. spring is produced by a force exerted in an opposite directionto F which can be continuously sustained, and which I may refer to as abalancing holding force,

F0. The energy used in obtaining the potential energy stored up ineachof the printing agencies is derived from a local source and need notbe transmitted over. the lines. To render the potential energy in eachagency available to drive the same through a printing cycle, as I shallspecify in the claims, I cause an electrical impulse transmitted overthe telegraph lines to momenexpended in driving the printing member downand back, through its printing cycle. The energy necessarily transmittedfrom the telegraph line for this method of operation may be far lessthan that needed by any other system which has ever been proposed beforeto my knowledge. In other systems the energy transmitted by the currentimpulse acts directly on the printing members oron intermediate parts,such as relays, with a low speed of operation and greater diflicultythan by my method.

thus described my invention,

Havin what I caim is:

l. The method of printing telegraphic sig nals transmitted at high speedwhich consists inthe following steps: (-1) 'applyin a potential drivingforce to each one o a group of printing agencies, and maintaining thesame normally inactlve by a balancmg holding force continuouslysustained in opposition to said driving force; (2) transmitting inpredetermined order, a succession of single impulses of individuallydifferin character, the effective part of each I impu se being ofshorter duration than one? complete cycle of operation of'one of thesaid.,;;lprinting agencies; (3)"causing each of sand impulses, accordlngto its character, to

selectively and directly affect "one of said printing agencies so astoinstantly Junbalance the-Jsame by weakening""'the holding""'" forceduring the persistence'of the impulse nly, 11nd,"; thereby 4 releasingthejpoten tial driving force applied to the selected 7 printing agencyand causing the same to'.

produce a characteristic .mark on a record surface having suitable feedmovement, all of the printing agencies being operated-in the same orderas the order in whichtheimpulses are transmitted.

2. The method of printing telegraphic'signals transmitted at high speedwhich consists in the, following steps: (1) applying a potential drivingforce to each-one of a group of printing agencies, and maintaining thesame normally inactive by a balancing holding force continuouslysustained in opposition to said driving force; (2) transmitting in predetermined order a succession of.single impulses of individuallydiffering character, the effective part or operative period of eachimpulse being oflshorter duration than one complete cycleof operation ofone of the said printing agencies, the period of the cycle of operationaforesaid being not greater than the shortest period betweentheeffective parts of two successive impulses;

(3) causing each of said impulses, according to its character, toselectively and directly affect one of said printing agencies so as toinstantly unbalance the same by weakening the holding force during thepersistence of the impulse only, and, thereby, (4) releasing thepotential driving force applied to the selected printing agency andcausing the same toproduce a characteristic mark on a-record surfacehaving suitable feed movement, all of the printing agencies beingoperated in the same order as the order in which the impulses aretransmitted.

3. The method of printing telegraphic signals transmitted at high speedwhich consists in normally maintaining applied to each of agroup ofprinting agencies, a potential driving force adapted to drive the samethrough a printing cycle, retaining said agencies normally inactive by aholding force sustained in opposition to said driving force,transmitting selectively to said agencies electrical controllingimpulses, and translating said impulses into controlling forces inopposition to said holding forces whereby the holding forces are reducedbelow their effective limit and the driving forces become active todrive the agencies through the printing cycles in the order of theirselection. 1

4:. The method of printing telegraphic signals, which consists intransmitting to a group of printing agencies having independentlydetermined individual periods of operation, controlling impulses varyingin character and adapted to selectively affect the agencies to cause thesuccessive operation of those necessary to print the characters desired,effecting operation of the printing agencies in unison with thetransmission of the controlling impulses, but deeration, con-trollingimpulses varying in character and adapted to selectively affect theagencies to cause the successive opera tion of those necessary to printthe characters desired, effecting operation of the printingagenciesthrough the direct influence of said'impulsesand in unison with thetransmission thereof but determining the periods of duration of theindvidual impulses independently of the individual periods of operationof said agencies, and so that each agency when actuated may individuallycomplete its cycle' of operation without further control.

\ .6. The. method of printing telegraphic signals which consists inmagnetically re- -taining a group of printing elements under tensionsufiicient to 'dri-ve'them through a printing cycle, transmittingto saidgroup of printing elements controlling electrical impulses varying incharacter, translating said impulses into magnetic forces in opposltionto the magnetic retaining forces acting on said group, whereby theprinting elements are selectively and variably released and carriedunder their tension successively through the printing cycle, andlimiting the duration of said electrical controlling impulses to aperiod not greater than the period of said printing cycle whereby at theclose of the printing cycle the elements are again magnetically retainedunder tension.

7. The method of' printing telegraphic signals which consists inpotentially applying to each of a group of printing agencies a tensionadapted to vibrate the same individually through a printing cycle,magnetically retaining said agencies against vibration, transmitting tosaid agencies electrical controlling impulses varying in characteraccording to the signals it is desired to print and thereby selectivelyreleasing said printing agencies, and predetermining themaximum periodbetween successive controlling impulses so that it is greater than thenatural period of vibration of the printing agencies.

8. The method of printing telegraphic signals which consists inretaining the individual elements of a group of printing agencies, undera tension sufficient to vibrate the same through a printing cycle, bypermanently active magnetomotive forces differing in intensity and"polarity, transmit- ILG permanent'magnetomotive forces with translatedmagnetomotive forces of equal value and opposite polarity, whereby theformer are individually, partly or wholly neutralized and the agenciesselectively released to print the desired signals.

9. The method of transmitting and receiving telegraphic signals at highspeed which consists in the following steps: 1) transmitting a periodiccurrent over the line, and producing predetermined changes in theindividual current waves or impulses corresponding to the signal desiredto be transmitted; (2) causing an electromagnetically controlledprinting device to respond 2 directly to said current changes, saidprinting device being proportioned and adjusted to have a natural periodof vibration of, the

same order as that of the line impulses, and so that the time requiredfor a complete cycle of operation of the printing device in prmting acharacter will be greater than the.

duration of the eifective part of the line impulse which produces suchaction, but less than the time interval between the beginning ofsucheflective impulse or part of an impulseand the beginning of theeffective CARL KINSLEY.

Witnesses:

CHAS. O. Pnocron, GERALD T. PARKER.

Copies of this-patent may be obtained for five cents each, by addresslngthe "Commissioner of Patents.

Washington, D. G."

